DESCRIPTION: Two factors determine the ultimate impact of health promotion programs: the ability of interventions to influence health outcomes and the extent of exposure and participation in the program by the population at risk. Research to date on school-based health promotion programs has shown that school- based programs can be both efficacious and effective. However, little is known about how to adequately diffuse effective programs available on a large scale and how to maintain the level of implementation demonstrated during the research phase. The Child and Adolescent Trial for Cardiovascular Health (CATCH) study presents a unique opportunity to study the institutionalization of a school-based health promotion program in a natural observation study. CATCH is the largest school-based health promotion study ever funded in the United States, including schools from four geographical areas and representing students from diverse cultural and ethnic groups. The aims of this study are to assess the degree to which CATCH intervention goals (reduction of the fat and saturated fat offered in school meals, increase in the amount of time students spend in moderate to vigorous physical activity in PE class, 90 minutes of school time devoted to PE class, a policy of no tobacco use and implementation of the CATCH curriculum) are being maintained or institutionalized in the original 56 CATCH intervention (maximally exposed) schools and the degree to which these same CATCH intervention outcomes are being achieved in the 20 randomly selected former CATCH control (minimally exposed) schools. To determine the influence of secular trends, these outcome measures will also be assessed in 12 newly recruited (unexposed) schools. Measures of school climate, teacher and staff characteristics, school turbulence and school facilities and resources will be assessed to help explain the variation in the degree of institutionalization in the CATCH intervention and control schools. The significance of the results from the proposed study reside in their future utility to plan for the diffusion of health promotion programs, including the identification of barriers and facilitating factors involved in the institutionalization of such programs.